The present invention relates to a new and improved device for wrinkle free spreading of the tubularly shaped package making film after it leaves the lower end of a forming and filling nozzle tube and is then sealed across the film into individual packages by means of the customary pull down and sealing mechanism associated with machines of this type.
As pointed out in U.S. Pat. No. 4,829,745, one of the problems that has occurred in vertical form, fill and seal machines has been that wrinkles tend to form along the edge seal lines of the packages during the edge sealing operation which is accomplished by means of the customary sealing and pull down mechanism. This mechanism functions to seal each succeeding bag or package and pull the package making film downwardly a package increment at a time below the discharge or filling end of the vertical forming and filling tube of the machine.
According to U.S. Pat. No. 4,829,745 the spreader device disclosed therein is used for spreading the formed film in coordinated relation with operation of the sealing and pull down to eliminate wrinkles that otherwise would develop along the edge seal lines because of the loading of the package with product. However, that mechanism can be substantially improved as will become apparent herein. In order to minimize the need for background description details, U.S. Pat. No. 4,829,745 is incorporated herein by reference.